Image forming apparatus having resin frame for supporting photosensitive drum

Abstract

An image forming apparatus including an image forming unit, a first frame, and a first beam, is provided. The image forming unit includes a photosensitive drum which is rotatable about a rotation axis and a developer device which supplies developer agent to the photosensitive drum. The first frame is made of resin and formed in a shape of a plate. The first frame is arranged on one end, along an axial direction of the rotation axis of the photosensitive drum, of the image forming unit. The first beam is formed in an elongated shape. The first beam is arranged along and fixed to a planar face of the first frame. The first beam includes a resilient part configured to be resiliently deformable in a direction orthogonal to the planar face of the first frame.

What is claimed is: 
     
       1. An image forming apparatus, comprising:
 an image forming unit comprising a photosensitive drum configured to be rotatable about a rotation axis and a developer device configured to supply developer agent to the photosensitive drum; 
 a first frame made of resin and formed in a shape of a plate, the first frame being arranged on one end, along an axial direction of the rotation axis of the photosensitive drum, of the image forming unit; and 
 a first beam formed in an elongated shape, the first beam being arranged along and fixed to a planar face of the first frame, 
 wherein the first beam comprises a resilient part configured to be resiliently deformable in a direction orthogonal to the planar face of the first frame. 
 
     
     
       2. The image forming apparatus according to  claim 1 , wherein the resilient part is formed in a shape of a bar having a plane arranged along the planar face of the first frame. 
     
     
       3. The image forming apparatus according to  claim 1 ,
 wherein the first beam comprises two end parts, the end parts being configured to be more difficult to deform than the resilient part; and 
 wherein the resilient part is formed separately from the end parts, the resilient part being arranged in a position between the end parts and connected to each of the end parts. 
 
     
     
       4. The image forming apparatus according to  claim 3 , wherein the resilient part is fixed to the end parts by screws. 
     
     
       5. The image forming apparatus according to  claim 1 , wherein the first beam is arranged to overlap the image forming unit at a longitudinal central part thereof, when projected along the axial direction, while longitudinal ends of the first beam are arranged on outer sides of the image forming unit. 
     
     
       6. The image forming apparatus according to  claim 1 , further comprising:
 a second beam formed in an elongated shape, the second beam being arranged along and fixed to the planar face of the first frame, 
 wherein the second beam is arranged to intersect the first beam. 
 
     
     
       7. The image forming apparatus according to  claim 6 , wherein the second beam is arranged to overlap the resilient part of the first beam when projected along the axial direction. 
     
     
       8. The image forming apparatus according to  claim 6 ,
 wherein the image forming unit comprises a plurality of image forming units, the plurality of image forming units being arranged to align along an aligning direction, which is orthogonal to the axial direction; 
 wherein the first beam is arranged to longitudinally extend orthogonally to the aligning direction and to the axial direction; and 
 wherein the second beam is arranged to longitudinally extend along the aligning direction. 
 
     
     
       9. The image forming apparatus according to  claim 8 , further comprising:
 a drawer configured to support the plurality of image forming units, the drawer being supported by the first frame movably to move along the aligning direction, 
 wherein the second beam is arranged to overlap the drawer when projected along the axial direction. 
 
     
     
       10. The image forming apparatus according to  claim 1 , further comprising:
 a second frame arranged to face the first frame across the image forming unit; and 
 a connecting frame configured to be connected to the first frame and the second frame, 
 wherein one of longitudinal ends of the first beam is arranged to overlap the connecting frame when projected along the axial direction. 
 
     
     
       11. The image forming apparatus according to  claim 10 , further comprising:
 a second beam formed in an elongated shape, the second beam being arranged along the planar face of the first frame to intersect with the first beam and fixed to the first frame, 
 wherein the other one of the longitudinal ends of the first beam is engaged with the first frame; and 
 wherein the second beam is arranged in a position between the first beam and the first frame. 
 
     
     
       12. The image forming apparatus according to  claim 1 ,
 wherein a spring electrode to supply electricity to the image forming unit is arranged on the first frame; and 
 wherein the spring electrode is arranged in a position between the first frame and the image forming unit in a compressed condition. 
 
     
     
       13. The image forming apparatus according to  claim 1 ,
 wherein the first frame comprises a plurality of substrate supports, which are configured to support a substrate, the substrate being configured to supply electricity to the image forming unit via a spring electrode, and 
 wherein the spring electrode is arranged in a position between the substrate and the image forming unit in a compressed condition. 
 
     
     
       14. The image forming apparatus according to  claim 13 ,
 wherein the plurality of substrate supports are arranged on an opposite side from the image forming unit across the first frame; and 
 wherein the first frame comprises a through hole, in which the spring electrode is arranged to penetrate there-through. 
 
     
     
       15. The image forming apparatus according to  claim 1 , wherein the first beam is made of metal.